The Uniform Criminal Reporting Program of the U.S. Department of Justice defines burglary as the unlawful entry of a structure to commit a felony or theft. Burglary is generally categorized into three subclassifications: forcible entry, unlawful entry where no force is used and attempted forcible entry. In 1985 the number of burglaries in the U.S. was estimated at over three million separate offenses. In 1986, this figure had increased a startling 5.5 percent reflecting a rate of 1,344 offenses per hundred thousand inhabitants. Thus, burglaries account for 25 percent of all crime index offenses.
Two out of every three burglaries are residential in nature. Seventy percent of all burglaries involve forcible entry. Burglary victims suffered a combined loss in 1986 of approximately three billion dollars, with the average loss per burglary set at almost a thousand dollars.
In order to protect life and property, a number of anti-burglary devices have been developed by others in the past. These include alarms and silent intrusion detection devices which are devised to alert building occupants of an unauthorized entry into the premises. However, alarms do little to protect against forcible entry, although they may occasionally thwart a burglary by frightening an intruder.
A more practical method of preventing unwanted intrusion by a burglar is to provide intrusion-resistant premises. This is commonly achieved to varying degrees of success by conventional locks such as dead bolt assemblies in doors and windows. Other devices such as "charley bars" have provided some additional fortification of doors, although there usefulness is limited and they are generally inconvenient to implement.
Of particular concern are those intruders that gain entry by first knocking or ringing a door bell, only to force themselves into the premises when the lawful occupant unlocks the door to determine who is calling. To prevent such entry, door "peepholes" which may include wide angle lenses or the like have been provided to allow an occupant to visually inspect and verify the identity of the caller. Unfortunately, doors which are solid enough to withstand attempted forceful entry are often insulative to sound which makes it difficult to interrogate an unrecognized intruder to determine the nature of the call. To this end, security chains have been developed by which a limited clearance or opening of the door can be achieved while still maintaining some protection against entry.
Security chains commonly include means for mounting one end of the chain to a molding which circumscribes the door frame and a second mounting means having a slot or channel which is secured directly to the door. A member attached to the free end of the chain is adapted to be closely and securely received by the door mounting means. Thus, when one wishes to speak to a suspect caller, one merely secures the free end of the chain to the door mount and unlocks the door. The door can then be opened a distance regulated by the length of the security chain.
As law enforcement personnel know all to well, the fallacy of security chains is that they are inherently structurally weak. Very little force is necessary to break the links of a typical security chain due to their low tensile strength. Moreover, even an intruder of moderate build can very often ram a door with a sufficient force to pull the chain mounting means from their moorings, at times separating the door frame molding from underlying structures. Therefore, security chains are many times inadequate to prevent intrusion and may in fact give an occupant a false and fatal sense of security where none exists.
A solution to the problems inherent in security chains, one which still permits a door to be opened slightly to interrogate a caller, is the provision of a door stop member mounted directly to the floor of a room within the arc of passage of the door as it swings upon its hinges. In use, a door stop member is mounted on a floor bracket which is adapted to rigidly receive the stop member. One such device is disclosed in U.S. Pat. No. 3,833,963 to Waters. There, a door stop comprising a channeled floor plate and a stop member is disclosed. The plate is mounted in the floor surface such that the floor surface and the top of the plate lie in the same plane. In this mode the door is free to swing through its complete arc of passage. When the movement of the door is to be impeded, a separate component, the stop member, is inserted into the floor mount via its channels where it is then locked into place. While the concept is viable, the device is impractical due to its inconvenient method of operation.
Although appropriate as stop members, the devices disclosed in U.S. Pat. No. 4,601,502 to Van Dyke, U.S. Pat. No. 4,601,504 to Wolf and U.S. Pat. No. 4,462,623 to Grant all suffer from numerous drawbacks including their limited ability to withstand the substantial lateral forces which would be exerted on their stop rods or pins. Not only would the stop rods most likely bend if not formed of strengthened materials, their delicate and complicated spring actuating mechanisms may be irreparably damaged in response to any significant force. Moreover, it is clear that in order to be operated conveniently with one's foot, the cross-sectional area of the telescopic rods would have to be extremely large. For these and other reasons, these pin-like devices are wholely impractical as sturdy door security devices.
A more realistic approach is disclosed in U.S. Pat. No. 3,805,322 to Serrano. There, unlike the aforementioned devices, a pivotable stop member is provided in a housing which is mounted in a floor cavity. In one mode of operation, the device is retracted within the floor cavity and in the second mode of operation, the pivotable stop member is raised above the floor surface to engage and thus stop the arcuate movement of the door. It is stated in Serrano that the device can be operated with one's foot. However, from close inspection, it is apparent that although it is possible to raise the stop member by the complicated process of turning a floor mounted serrated disc with one's foot, it is virtually impossible to lower the stop member without reaching down to the floor with one's hand to release a support strut or finger. In fact, once the strut is released it is still necessary to once again turn the serrated disc precisely back to its initial position, requiring rotational movement against the opposing force of the biasing member. Further, the thin stop member, its precarious attachment to the housing, and the fragile support strut all combine to create far too many weak links for substantial safety against intrusion.
The present invention overcomes these various deficiencies in the prior art devices by providing a unique, truly foot-operated safety door stop having superior strength of construction, ease of operability, and which is economical and vitually maintenance free.